Over the past two years, I have been travelling between the wilder landscapes of the British Isles. Wherever I have gone, I have found testimonies to the deep affection in which these landscapes are held. These testimonies have taken many forms. I have found poems tacked up on the walls of bothies. Benches set on lakesides or low hill passes, commemorating the favourite viewpoint of someone now dead. A graffito cut into an oak's bark decades previously, which had stretched and spread with the tree's growth, so that it looked like lettering on a balloon. Once, kneeling to drink from a pool near a waterfall, I found a brass plaque set discreetly beneath a rock: "In memory of George Walker / Who so loved this place."

Such markers are the indicators of a process which is continuously at work in the British Isles: the drawing of happiness from landscapes. Happiness - and the repertoire of emotions which go by the collective noun of "happiness": hope, joy, glee, wonder, surprise, calmness and others. Every day, millions of people find themselves deepened and dignified by their encounters with particular places.

Most of these places are not marked as special on any map. They become special by acquaintance. A bend in a river, the junction of four fields, a stretch of old hedgerow, or a fragment of woodland glimpsed from a road regularly commuted; these will do. So too will experiences: transitory, but still site-specific. A sparrow-hawk sculling low through the sky. A cross-hatching of cirrostratus clouds. The fall of evening light on a boulder. A pigeon feather caught on a strand of spider-silk, twirling in mid-air like a magic trick. Daily, throughout Britain and Ireland, people are brought to sudden states of awe by encounters such as these: encounters whose power to move us is beyond expression, but also beyond denial.

Very little is said publicly about these encounters. This is partly because those who experience them feel no need to broadcast their feelings. A word is exchanged with a friend or partner; a photograph is kept; a note is made in a journal, a line is added to a letter. Many encounters do not even attain this degree of voice. They stay unarticulated, part of private thought. They return as memories: recalled while standing on a station platform packed tightly as a football crowd, or lying in bed unable to sleep, while the headlight beams of a passing car pan round the room.

The second reason why little is said about these encounters is that we find it hard, as a culture, to express this sense of what landscapes do to us. We have devised highly efficient metric systems for saying what they do for us: cost-benefit analyses of per-hectare yield, or tourist draw. But it is difficult to speak of their effects upon us without lapsing into the blithe or the mystical. And so, on the whole, we remain silent.

Yet even as this great and legitimate process of consolation continues, so the landscapes capable of supplying it diminish. Over the last 75 years, apocalypse has fallen upon the environment. The statistics of damage are familiar and often repeated, more as elegy now than as protest. In England, between 1930 and 1990, 50% of hedgerow mileage was grubbed up. Fifty per cent of ancient woodland was cleared, or replaced with conifer plantation. Ninety-seven per cent of florally diverse lowland grassland was ploughed up, built over or tarmacked. Seventy-five per cent of heathland has been rendered into agri-prairie, or re-categorised as waste ground, and developed. One in five plant species in the British Isles is now classed as "threatened". Across Britain and Ireland, rare limestone pavements have been cracked up and sold as rockery stones, boglands have been gouged out and dispensed as back-garden peat. Rivers have become sumps for agri-chemicals. Only a tiny and dwindling proportion of mountain terrain is more than five miles from a motorable road. Remoteness has been all but abolished. Wild land - in the radical etymological meaning of that word as "self-willed land", land left entirely to its own devices - does not exist.

We live, as John Fowles wrote in 1970, in the era of "the plastic garden, the steel city, the chemical countryside". We live in an era, too, when it has become in the interest of powerful commercial forces to erase the particularity of place, and to suppress the local distinctiveness of what little landscape has survived modernity's onslaught.

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Last year, I was approached by OneLife, the "lifestyle" magazine of Land Rover, which is sent out to Land Rover owners in more than 60 countries and is, according to its own modest marketing, "worthy of the world's best coffee tables". OneLife had a writing commission in mind for me. I would be flown out to the Caicos Islands in the Caribbean for a three-day stay. There, I would conduct a "beach-based" interview with "the world-famous freediver Tanya Streeter": the conceit being that I, as a mountaineer, and Streeter as a diver, were both explorers of the vertical. I would stay in the best hotel on the islands. Naturally, all expenses would be covered and all transport pre-arranged. The fee for the subsequent 2,000-word article would run to a generous five-figure sum.

If only it had not been Land Rover making the offer. How ardently I wished for it not to have been Land Rover.

Transport is the fastest-growing source of carbon dioxide production in Britain: transport emissions increased by 50% between 1990 and 2002. In the main, this is due to the unsustainable growth in air travel. It is also, however, down to the massively burgeoning 4x4 market. Sales of 4x4s grew by 12.8% in this country last year, to 179,000 vehicles: more than double the number sold 10 years ago. Only 12% of 4x4s are ever driven "off-road", 40% never leave the city.

One cost of the 4x4 boom is long-term environmental. Big 4x4s in urban conditions manage 13 miles to the gallon; the very biggest manage four. Four miles to the gallon. To drive a 4x4, given the disastrous rapidity of climate change, is to demonstrate the same reverse-denial of the lung-cancer victim who continues to smoke cigarettes after diagnosis.

The other cost is short-term personal. If you are driving a small car and collide with a 4x4, you are 12 times more likely to die than if the collision was with another small car. Redwood, the magazine company which produces OneLife, speaking proudly of its publication's print quality, hails OneLife's "full-bleed imagery". Indeed.

My OneLife contact sent me two issues of the magazine. It was lavishly produced, and "landscape" was its glamour, its sales pitch. On every page, Land Rovers romped across winter hillsides, over desert dunes, along boulder-cobbled river-beds. There were glossy centrefold spreads of eco-porn: thrusting mountains, brothel-pink sunsets. Andy Goldsworthy-ish images of cracked mud patterns served as wallpaper between text boxes. Nature was being used to sell a product which embodies the principles by which nature must not be understood.

OneLife - what a happy holistic world the name evokes! - is of course only conforming to large-scale 4x4 advertising strategies. You will be familiar with them from billboards and television commercials: gleaming semi-militarised vehicles ploughing through a swamp, or along a cliff-top, before slewing to a rakish halt at a view-point. The vehicles' names - the "Touareg", the "Bedouin" - are repellently shameless steals from aboriginal cultures, designed to raise atavistic hairs on the backs of consumers' necks.

4x4 advertising is dedicated to manipulating landscapes into generic forms. All that it requires of a landscape is that it evoke the idea of challenge - something resistant to be conquered, something natural to be tamed. A river is valued for its difficulty of fording. A mountain for its dramatic and nameless escarpments. No landscape can be only itself: it must represent an obstacle of some sort.

The hypocrisies of 4x4 marketing are dark, multiple and pernicious. Everything about the product urges us to the wrong relationship with our environment. The vehicles themselves are the gargoyle of a rampant and acrid form of individualism: gated communities of one. They bespeak the urge to dominate and crush which is at the root of what Ivan Illich called "the 500-year war on sustainability". They expound a vision of an unspoiled and untroubled land, even as they market the tools of its further wreckage.

The massive sales growth of the 4x4 is one dismaying example among many of the gap which currently exists between knowledge and place. Each month, it seems, that gap widens. Apocryphal stories circulate: about the schoolchildren who do not know that milk comes from cows, or who cannot identify a cucumber from a line-up of vegetables. In April of this year, the Woodland Trust published research showing that 94% of British children are unable to identify common native trees - beech, ash, birch, hazel - from their leaves, and that more than 40% of seven to 10-year-olds have never visited a wood.

And as that gap widens, so the "line of predestined fall", as Tim Robinson calls it, yawns at our feet. For the separation of knowledge and place moves us slowly towards a society in which it is increasingly unnecessary for us to be aware of where we live, beyond the housekeeping of our own private zones. Once this awareness has lapsed, then landscapes beyond those private precincts become easier to manipulate for ill. Once the networks of origin, cause and process which exist between environment and life are forgotten, then we are left with a diminished idea of how individual parts of landscapes are threatened, by pollution or mismanaged development. As Barry Lopez has put it:

The more superficial a society's knowledge of the real dimensions of the land it occupies becomes, the more vulnerable the land is to exploitation . . . for short-term gain. The land, virtually powerless before political and commercial entities, finds itself finally with no defenders. It finds itself bereft of intimates with indispensable, concrete knowledge.

How, though, is it possible to regain such "concrete knowledge"? How is it possible to restore particularity to place, to provoke intimacy, or a sense of what is remarkable in a stretch of land? To come to know a place - its textures, its species, its interplay of scape and space, the archive of its weathers, the wind-history of its trees - is long work. Not all places can be known by all people in such a way.

So we are brought back to literature, the cultural form which is peerlessly good at annotating and evoking a place's particularity. Each of the writers I have discussed in this column over the past weeks has spent years, sometimes decades, getting to know their terrains. Their prolonged acquaintance with a place has allowed the slow capillary creep of knowledge to occur.

In the face of the colossal forces currently ranged against the environment, resistance can seem futile. As a society - with our societal belief in consumption as a right, and desire as a finer force than need - we seem to tunnel unswervingly on, deaf to the noise of the roof and walls collapsing behind us. Nevertheless, I want to offer a suggestion for one way to close the gap between knowledge and place. It might close it only by a sliver of a degree, but all such slivers and all such degrees are presently required.

The suggestion - which echoes a similar call made by Lopez exactly 20 years ago in America - is that a series of classic works of nature writing from England, Scotland, Wales and Ireland should be established and published. Such a series would not kowtow to the doubtful idea of a "national" literature. Instead, it would be a series of local writings, which concentrated on particular places, and which worked always to individuate, never to generalise. It would not vaunt a little-islandism, nor would it be blind to the spoliation of the landscape which has occurred. It would not adore landscape as a site for the exercise of middle-class nature-sentiment - a gymnasium for the sensitive.

It would, however, honour a form of care, and a form of attention, to the landscapes of the British Isles. It would discover in landscapes values which transcend the commercial and the consumerist. And it would restore to visibility a tradition of nature writing which has slipped from view these past 50 years.

Such a series, as I imagine it, would reach backwards in time as well as outwards in space: to Gilbert White's A Natural History of Selborne (1789), to Duncan Ban MacIntyre's great long southern Highland poem, "In Praise of Ben Dorain" (1750s), to Sir Gawain and the Green Knight (late 14th-century), and to the medieval Irish saga of Buile Suibhne (Sweeney Astray, in Seamus Heaney's translation), which travels between the ancient wild places of Ulster. It would of course include Tim Robinson in Aran and Connemara, J A Baker in coastal Essex - the wonderful lost land of the Dengie Peninsula - Jim Perrin in Snowdonia, Henry Williamson's Tarka the Otter in Dartmoor. Other possibles would be Ronald Blythe's Akenfield in Suffolk; Bruce Chatwin's On the Black Hill for the Welsh marches; Gavin Maxwell on Camusfearna; Geoffrey Household's Rogue Male for Dorset; sections from Cobbett's Rural Rides; Auden on north Yorkshire; W H Murray on Glen Coe. These are only the most obvious names. There would be many more, as yet unknown to me: in other languages (Gaelic, Welsh, Breton), other genres (scientific studies, prose-poems); and other, less immediately glamorous, landscapes.

There would, to my mind, be two prerequisites for a book to be included in this series. Firstly, it would have to evince the belief that - in Lopez's fine phrase - the "fate of humanity and the fate of nature are inseparable". Secondly, it would have to suggest, however obliquely, that the natural environment must be approached not with a view to conquest, acquisition and short-term use, but according to the principles of restraint and reciprocity. In this sense, each book in the series would be a subtle work of hope. Each would set itself against the unbalance and ignorance of the present time. Each would guide us some way towards the common ground.

If you have suggestions for books to include in such a library, please write to